Add nexthop cache fresh check method.
Add nexthop cache fresh check method.

anarkiwi/faucet,wackerly/faucet,shivarammysore/faucet,gizmoguy/faucet,gizmoguy/faucet,shivarammysore/faucet,REANNZ/faucet,mwutzke/faucet,mwutzke/faucet,byllyfish/faucet,isomer/faucet,trentindav/faucet,trentindav/faucet,Bairdo/faucet,isomer/faucet,faucetsdn/faucet,Bairdo/faucet,trungdtbk/faucet,anarkiwi/faucet,byllyfish/faucet,wackerly/faucet,faucetsdn/faucet,REANNZ/faucet,trungdtbk/faucet